Electric heating – Heating devices – Combined with container – enclosure – or support for material...
Patent
1997-01-06
1999-06-01
Walberg, Teresa
Electric heating
Heating devices
Combined with container, enclosure, or support for material...
219410, 219411, 392411, 1562728, 1562755, 419 45, 419 47, 362211, 313115, B29C 3508, B23K 2600, B22F 500, H05B 300
Patent
active
059085690
DESCRIPTION:
BRIEF SUMMARY
The invention relates to an apparatus for producing a three-dimensional object by laser sintering according to the preamble of claim 1.
An apparatus of this type is known from document WO 92/08566. In this apparatus an applied powder layer is heated by means of a circular ring radiator disposed horizontally above the powder layer. The laser beam for sintering is directed through the circular open inner surface of the ring radiator onto the powder layer. This apparatus is particularly advantageous for circular working areas.
In case that the working area, i.e. the working field for layerwise constructing the object to be formed, has a rectangular or square cross-section rather than a circular cross-section, a ring radiator is of limited use. The diameters of the ring radiator must be at least equal to the diagonal of the rectangular working area. This is a particular drawback for rectangular working fields having a length/width ratio in the range of 1.5 to 2, because it requires ring radiators having a large diameter. The required distance of the radiator from the surface and the simultaneous requirement of a practical installation of the radiator in a laser sintering apparatus contradict each other. Compromise solutions produce a non-uniform temperature distribution in the powder layer. However, a uniform temperature of the powder material, typically slightly below the melting temperature thereof, is imperative in view of a good quality of the object and a high safety of the process.
It is the object of the invention to provide an apparatus for producing a three-dimensional object by laser sintering which allows to improve the quality of the object and the safety of the process in particular when using a non-circular working area.
This object is achieved by an apparatus according to claim 1.
Further developments are defined in the subclaims.
Further features and advantages of the invention will be apparent from the description of embodiments with reference to the Figures. In the Figures:
FIG. 1 shows a schematic cross-sectional side view of the inventive apparatus;
FIG. 2 is a perspective view of the radiant heater arrangement above the working field;
FIG. 3 shows a top view of the radiant heater; and
FIG. 4 gives an example for a transfer behaviour of the powder layer to be heated.
As shown in FIG. 1 the apparatus comprises a tank 1 which is formed solely by a peripherally closed sidewall 2 having a rectangular or square contour. A working plane 30 is defined by the upper edge 3 of the sidewall 2 or of the tank 1, resp. A support 4 having an upper side 5 which is substantially plane and parallel to the upper edge 3 is disposed in the tank 1 for supporting the object 6 to be formed. On the upper side 5 of the support 4 there is the object 6 which is constructed in a manner described further below from a plurality of layers extending parallel to the upper side 5 and consisting of a powderous construction material 7 which can be solidified by electromagnetic radiation. The support 4 has a square or rectangular cross-section adapted to the contour of the sidewall 2 in a plane perpendicular thereto with an overall dimension which is slightly smaller than the clear opening of the sidewall 2. A circumferential seal is provided at the edge of the support 4 between the same and the sidewall 2 for providing a seal against penetration of building material 7. Moreover, the support 4 can be vertically displaced, i.e. in a direction parallel to the sidewall 2 of the tank 1, by means of an elevational adjustment device 9. Thus, the position of the support 4 relative to the working plane 30 can be adjusted.
A reservoir 10 for the building material 7 having an open top and a sidewall 100 is provided laterally of the tank 1. The upper edge 11 of the reservoir 10 at the portion of the sidewall 100 thereof adjacent to the sidewall 2 of the tank 1 is flush with the upper edge 3 of the tank 1. The reservoir 10 is permanently filled with the powderous building material 7 to a level slightly above the upper edge 11 adjacent to t
REFERENCES:
patent: 2369803 (1945-02-01), Sardeson
patent: 2499961 (1950-03-01), Lennox
patent: 4943928 (1990-07-01), Campbell et al.
patent: 5155321 (1992-10-01), Grube et al.
patent: 5352405 (1994-10-01), Beaman et al.
patent: 5658412 (1997-08-01), Retallick et al.
Sievers Tim
Wilkening Christian
EOS GmbH Electro Optical Systems
Neuner George W.
Pelham J.
Walberg Teresa
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